HPWC trips the breaker intermittently

GKR

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#1
Having a very puzzling problem with HPWC. It is the only load on a line with a 50A breaker, 4 GA copper wires. The rotary switch is set to 8 to limit the current to 40A. The charger shows no error messages and charges M3 fine. But when it is idle (either plugged into the car or not) it trips the breaker. This happens intermittently, maybe once or twice a day. Mostly it happens when no one at home and no other appliances in the house are being used. The breaker never tripped (yet?) while charging.

Any ideas of what may cause it or how to fix it? (I already offered my gas lawn mower as a sacrifice to the spirit of Nikola Tesla. That didn’t help.)
 

MelindaV

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#2
Having a very puzzling problem with HPWC. It is the only load on a line with a 50A breaker, 4 GA copper wires. The rotary switch is set to 8 to limit the current to 40A. The charger shows no error messages and charges M3 fine. But when it is idle (either plugged into the car or not) it trips the breaker. This happens intermittently, maybe once or twice a day. Mostly it happens when no one at home and no other appliances in the house are being used. The breaker never tripped (yet?) while charging.

Any ideas of what may cause it or how to fix it? (I already offered my gas lawn mower as a sacrifice to the spirit of Nikola Tesla. That didn’t help.)
was the WC installed by an electrician? if so, have them come back out and inspect it and the connections.
 

ADK46

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#3
First assumption should be that the breaker is doing its job: tripping when a fault in the wiring or WC occurs. An intermittent fault, a short, say. A ground fault if it is a GFCI breaker.

You might choose not to use it until fixed, at least not while people are sleeping.

If you replace it with a new breaker, and that one also trips, you'd have confirmation of genuine trouble. I would disconnect the WC and see if that's the cause. If not, you'll have the difficult job of finding where the wiring has failed - or abandoning it where hidden and putting in new. Put out mice poison.

If it doesn't trip, that would suggest the old breaker was at fault - done. Since #4 wire is easily capable of 60A, you might consider swapping in a 60A breaker and changing the WC setting, so you could get the full 48A while charging - the Model 3's maximum. But note that the electrician may have had other reasons to limit the circuit to 50A - a long run, other loads, etc..

[I am not an electrician.]
 

Toadmanor

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#4
Well, I had a similar problem. I do not use the HPWC but rather a 14-50 NEMA outlet I hooked up using #6 wire. The breaker was a 50 Amp GFCI breaker which previously had a hot tub hooked to it. The hot tub was sold several years ago and so the breaker just sat in the panel turned off.

I used that breaker to hook up for my Tesla. It was tripping randomly and for no seemingly discernible reason. I replaced the breaker with a $7.88 non GFCI breaker and it has worked flawlessly ever since.

I am a bit older now so no more tripping for me!
 
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